I wasn't referring to identification (I even specifically mentioned that with respect to forensics). I'm talking about knowing the specific content of a subject

I wasn't referring to identification (I even specifically mentioned that with respect to forensics). I'm talking about knowing the specific content of a subject's genome, the issue of primary concern. Even if you know the genomes of both parents, you can only evaluate the probability of their offspring possessing any particular combination of alleles. The more alleles you wish to know about, the lower the probability that any particular model is correct. Regardless, you seem to completely disregard the argument for legal protections. If there were laws guaranteeing an absolute right to control one's genetic information, including who may possess it, much of this concern would go away.